Transcript Middle School Engineering- The Importance of Failure

Middle School EngineeringSucceeding through Failure
Jonathan Dietz
Weston Middle School
Weston, Massachusetts
Presentation based upon
Grade 7 Design-Construction- A 35-period
course taken by most students, as part of
arts rotation.
Theme: Engineering Design and technology
focusing on structural engineering.
Web Site:
http://www.weston.org/schools/ms/MCAS/DesCon7.htm
Questions to think about:
How do we encourage students to take
risks?
Why is it important that middle-school
students study engineering?
How do engineering skills apply outside of
engineering?
KEY IDEAS
What is
engineering?
Pizza Party Engineering
Example: You are inviting 10 friends for a
pizza party. How many pizzas do you
order?
Model: Kids eat two slices each, but some
eat three. There are 8 slices per pizza.
Engineering calculation:

(10 kids x 2 slices/kid)/ (1 pizza/8 slices)= 2.5
pizzas. So buy 3 pizzas.
What is Engineering?
Engineering is solving design problems
based upon a ( mathematical) model of
materials or processes.
A design should meet the needed
requirements for performance plus a
safety margin.
Trade-offs
Design in the real world always involves
trade-offs- cost vs performance, speed vs
torque.
You always have to compromise- there is
no perfect solution.
Examples: Big Dig too expensive- so
money was saved by deleting inner tunnel
box, not testing ceiling bolts, etc.
Technology is the knowledge of
how to make things.
How do you make a cake?
How do you make paper?
How do you build a house?
How do you make an Ipod?
Technology: the art of making
things
How do you install a bolt
in concrete?
Elegance
An elegant design
solution is the
simplest design which
performs as needed.
Designs should
always strive for
elegance.
Ganter Bridge by Christian Menn
Zakim Bridge
designed by
Christian Menn
Failure
Failure- properly analyzed- is critical to
engineering design
Engineering design depends upon
knowing the point at which a material or
design fails and how it failed.
Failure
Embracing failure is a
new concept for most
students.
Surviving failure is
difficult for all but the
best students.
In most classes,
failure is penalized.
How do we create a classroom
environment that encourages
student risk-taking, that embraces
failure as an opportunity for
learning?
Emphasize that students will not be
penalized for coming up designs that do
not work.
Have kids phrase answers, “ I’m only
guessing now, so . . . “
Competition and Failure
High-stakes competitions create few winners,
many losers, without an opportunity to re-design.
Middle-school engineering should NOT involve
high-stakes contests.
Measurement should be against a stated
criterion for performance, NOT against each
other.
Multiple Iterations
Designs should incorporate students
creating multiple versions of designs,
incorporating failure data from each trial
into the next version.
Prototypes should be easily revisable,
using cheap components such as paper,
straws and pins, or reusable materials
such as Legos.
Bridge Decks- Multiple Versions,
easily made
Grade 7 Design-Construction
Course alternates
material from videos,
discussion, and
computer simulations
with hands-on designchallenge projects.
Introductory Challenge- 1st iteration
Using 5 sheets of
paper and 12” of tape,
build the tallest freestanding tower you
can.
Tower must stand for
30 seconds.
Introductory Challenge- 2nd iteration
Introduce the concept
of rolling paper into
tight sticks using a
dowel as a jig- a
specially-built tool.
Share ideas and
concepts from first
version.
Introductory Challenge- 3rd iteration
Introduce technology
of cables( cotton
string)
Demonstrate use of
guy wires.
Rebuild using cables.
Minimum acceptable=
36” tall.
Direct Instruction- Tension and
Compression
Review forces acting on
towers- tension and
compression
Do Mini-Activities from
Building Big website
Build Concrete-block arch
Determine tensile
strength of cotton string
Bill Nye the Science Guy:
Structures.
Design Challenge #2- Straw and
Paper Bridges
Challenge: Using
paper, straws, pins,
and glue, build a
bridge which spans a
20” gap and supports
at least 8- 250cc
water bottles.
Part 1: Building the Deck
Students are asked to
build a model beambridge deck, using
pins and straws
and/or paper
cardstock.
Messing Around
Without prior instruction, students are
asked to build 2 or 3 versions of a model
bridge deck.
Test efficiency of bridge
Efficiency= carrying
capacity ( live load)/
weight of bridge
(dead load)
Revised Version: I-beams
Third Revision: Trusses
Students add Warrentype trusses to the
bridges, and re-test
the efficiency.
Testing and Modification
Bridges are tested to near failure. Failure
modes are observed, and the bridges
modified and re-tested.
Students are asked to describe in detail
how the bridge failed, and how it can be
strengthened.
Video: Building Big: Bridges
Emphasizes how bridges failed, and
how subsequent bridges were modified
in response.
Challenge #3-West Point Bridge
Designer
Part 1: Optimize a
sample design.
West Point Bridge Designer
Part 2: Design a
standard bridge, and
optimize cost.
Part 3: Original
Design
Part II- Construction Technology
Construction technology is taught using a
project-based approach
Activities vs Projects
Projects typically:
 Last 3 weeks or more
 Use non-disposable materials
 Emphasize technology rather than
engineering
 Difficult to modify
 Pride of ownership and craftsmanship
Architect: Frank Gehry
Model House Project
Week 1: Design
house on computer
using CAD homedesign software
House Construction Project
Week 2:



Build model foundation
(plaster)
Build sill beam
Frame walls
House Project
Week 3:



Finish framing
Frame roof
Add sample stairs, floors,
roofing, sheathing, and
insulation
Winding it all Up
MCAS Review of
Construction
Technology
Why study engineering?
To encourage more young men and women to
consider engineering as a career, through
participating in meaningful design challenges.
To enable our students to be active creators of
knowledge, including technology, not passive
consumers.
To learn how to understand complex systems.
To enable students to cope successfully with
failure, by seeing it, not as personal rejection,
but rather an opportunity for improvement .